Relative Pressure Sensor Drying Chamber Design

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Solution Overview

Problem

Relative pressure sensors face challenges in protecting against condensing moisture during temperature fluctuations, which can lead to humidity entering the sensor and damaging sensitive electronics.

Innovation Solution

The design incorporates a drying chamber filled with moisture-adsorbing material, surrounded by a moisture-permeable or impermeable wall, which is coordinated with a moisture-permeable reference pressure supply line to ensure effective drying of air and protection of sensor electronics, including a spiral-shaped reference pressure supply line and exchangeable drying chamber to manage saturation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reference pressure supply line is provided to supply atmospheric pressure to the measuring element, then the relative pressure measurement function is achieved, but moisture can enter the sensor through this opening and damage sensitive electronics

Engineering Contradiction:
Improverelative pressure measurement functionVSAvoidmoisture entry
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A drying chamber filled with moisture-adsorbing material is introduced as an intermediary component between the reference pressure supply line and the sensor electronics. This drying chamber acts as a mediator that allows atmospheric pressure to reach the measuring element while preventing moisture from damaging the electronics.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The drying chamber creates a protected environment by filling it with moisture-adsorbing material that maintains a dry atmosphere. This inert environment prevents moisture from reaching the sensor electronics while still allowing the reference pressure supply line to function.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Object-affected harmful factors

If the drying chamber is filled with moisture-adsorbing material to prevent moisture entry, then protection against condensation is achieved, but the drying chamber may become saturated and lose effectiveness

Engineering Contradiction:
Improvemoisture protectionVSAvoiddrying chamber effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The drying chamber is designed as an exchangeable component that can be replaced when saturated. This allows the system to discard the saturated drying material and recover effectiveness by installing a fresh drying chamber, ensuring continuous protection against moisture.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The system allows dynamic replacement of the drying chamber based on its saturation state. This dynamic approach ensures that the drying function is maintained by replacing the drying chamber when it becomes saturated, thereby extending the overall duration of effective moisture protection.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the reference pressure supply line is made moisture-permeable to allow air exchange, then drying efficiency is improved, but moisture can more easily penetrate into the sensor

Engineering Contradiction:
Improvedrying efficiencyVSAvoidmoisture penetration
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The drying chamber serves as an intermediary that receives moisture-permeable air from the reference pressure supply line and processes it through moisture-adsorbing material before the air reaches the sensor electronics. This mediator approach allows drying efficiency to be maintained while preventing moisture penetration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration effectively prevents moisture from entering the sensor, ensuring reliable pressure measurements even under temperature changes and extending the lifespan of the moisture-adsorbing material by managing air exchange and saturation.

Implementation Method 1

a drying chamber (4) arranged in the housing (12), which is filled with a moisture-adsorbing material (41)

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

the reference pressure supply line (3) is made of a moisture-permeable material at least in sections

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP2556369B1Relative pressure sensor
Publication Date: 2019.06.26 ENDRESS & HAUSER GMBH & CO KG
  • EP2556369B1 patent drawingFigure 1
  • EP2556369B1 patent drawingFigure 2
  • EP2556369B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a relative pressure sensor for determining a pressure (p1) of a medium, having a housing (12), having a measurement element (2), which is arranged in the housing (12), wherein an outer side of the measurement element (2), in contact with the medium, is charged with the pressure to be measured (p1), having a reference pressure supply (3) which supplies surrounding air to the measurement element (2) and having at least one drying chamber (4) arranged in the housing (12) for receiving air moisture. The invention is characterized in that the drying chamber (4) comprises a moisture-absorbing material (41) or is substantially made of the moisture-absorbing material (41), the moisture-absorbing material (41) is surrounded by a wall (51) at least in sections, which is made of a first moisture-permeable material, or is free from a wall at least in sections, and the reference pressure supply (3) is produced at least in sections from the first or a second moisture-permeable material, or the reference pressure supply (3) has an opening.